1. 09 1月, 2009 5 次提交
  2. 21 10月, 2008 2 次提交
  3. 13 10月, 2008 4 次提交
    • N
      md: remove space after function name in declaration and call. · d710e138
      NeilBrown 提交于
      Having
         function (args)
      instead of
         function(args)
      
      make is harder to search for calls of particular functions.
      So remove all those spaces.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      d710e138
    • N
      md: Remove unnecessary #includes, #defines, and function declarations. · fb4d8c76
      NeilBrown 提交于
      A lot of cruft has gathered over the years.  Time to remove it.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      fb4d8c76
    • A
      md: Convert remaining 1k representations in linear.c to sectors. · ab5bd5cb
      Andre Noll 提交于
      This patch renames hash_spacing and preshift to  spacing and
      sector_shift respectively with the following change of semantics:
      
      Case 1: (sizeof(sector_t) <= sizeof(u32)).
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      
      In this case, we have sector_shift = preshift = 0 and spacing =
      2 * hash_spacing.
      
      Hence, the index for the hash table which is computed by the new code
      in which_dev() as sector / spacing equals the old value which was
      (sector/2) / hash_spacing.
      
      Note also that the value of nb_zone stays the same because both sz
      and base double.
      
      Case 2: (sizeof(sector_t) > sizeof(u32)).
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      
      (aka the shifting dance case). Here we have sector_shift = preshift +
      1 and
      
      spacing = 2 * hash_spacing
      
      during the computation of nb_zone and curr_sector, but
      
      spacing = hash_spacing
      
      in which_dev() because in the last hunk of the patch for linear.c we
      shift down conf->spacing (= 2 * hash_spacing) by one more bit than
      in the old code.
      
      Hence in the computation of nb_zone, sz and base have the same value
      as before, so nb_zone is not affected. Also curr_sector in the next
      hunk stays the same.
      
      In which_dev() the hash table index is computed as
      
      (sector >> sector_shift) / spacing
      
      In view of sector_shift = preshift + 1 and spacing = hash_spacing,
      this equals
      
      ((sector/2) >> preshift) / hash_spacing
      
      which is the value computed by the old code.
      Signed-off-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NNeilBrown <neilb@suse.de>
      ab5bd5cb
    • A
      md: linear: Represent dev_info->size and dev_info->offset in sectors. · 6283815d
      Andre Noll 提交于
      Rename them to num_sectors and start_sector which is more descriptive.
      Signed-off-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NNeilBrown <neilb@suse.de>
      6283815d
  4. 24 7月, 2008 1 次提交
  5. 21 7月, 2008 4 次提交
    • N
      md: Protect access to mddev->disks list using RCU · 4b80991c
      NeilBrown 提交于
      All modifications and most access to the mddev->disks list are made
      under the reconfig_mutex lock.  However there are three places where
      the list is walked without any locking.  If a reconfig happens at this
      time, havoc (and oops) can ensue.
      
      So use RCU to protect these accesses:
        - wrap them in rcu_read_{,un}lock()
        - use list_for_each_entry_rcu
        - add to the list with list_add_rcu
        - delete from the list with list_del_rcu
        - delay the 'free' with call_rcu rather than schedule_work
      
      Note that export_rdev did a list_del_init on this list.  In almost all
      cases the entry was not in the list anymore so it was a no-op and so
      safe.  It is no longer safe as after list_del_rcu we may not touch
      the list_head.
      An audit shows that export_rdev is called:
        - after unbind_rdev_from_array, in which case the delete has
           already been done,
        - after bind_rdev_to_array fails, in which case the delete isn't needed.
        - before the device has been put on a list at all (e.g. in
            add_new_disk where reading the superblock fails).
        - and in autorun devices after a failure when the device is on a
            different list.
      
      So remove the list_del_init call from export_rdev, and add it back
      immediately before the called to export_rdev for that last case.
      
      Note also that ->same_set is sometimes used for lists other than
      mddev->list (e.g. candidates).  In these cases rcu is not needed.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      4b80991c
    • N
      md: only count actual openers as access which prevent a 'stop' · f2ea68cf
      NeilBrown 提交于
      Open isn't the only thing that increments ->active.  e.g. reading
      /proc/mdstat will increment it briefly.  So to avoid false positives
      in testing for concurrent access, introduce a new counter that counts
      just the number of times the md device it open.
      Signed-off-by: NNeilBrown <neilb@suse.de>
      f2ea68cf
    • A
    • A
      md: Make mddev->array_size sector-based. · f233ea5c
      Andre Noll 提交于
      This patch renames the array_size field of struct mddev_s to array_sectors
      and converts all instances to use units of 512 byte sectors instead of 1k
      blocks.
      Signed-off-by: NAndre Noll <maan@systemlinux.org>
      Signed-off-by: NNeilBrown <neilb@suse.de>
      f233ea5c
  6. 11 7月, 2008 2 次提交
  7. 01 7月, 2008 1 次提交
    • D
      md: resolve external metadata handling deadlock in md_allow_write · b5470dc5
      Dan Williams 提交于
      md_allow_write() marks the metadata dirty while holding mddev->lock and then
      waits for the write to complete.  For externally managed metadata this causes a
      deadlock as userspace needs to take the lock to communicate that the metadata
      update has completed.
      
      Change md_allow_write() in the 'external' case to start the 'mark active'
      operation and then return -EAGAIN.  The expected side effects while waiting for
      userspace to write 'active' to 'array_state' are holding off reshape (code
      currently handles -ENOMEM), cause some 'stripe_cache_size' change requests to
      fail, cause some GET_BITMAP_FILE ioctl requests to fall back to GFP_NOIO, and
      cause updates to 'raid_disks' to fail.  Except for 'stripe_cache_size' changes
      these failures can be mitigated by coordinating with mdmon.
      
      md_write_start() still prevents writes from occurring until the metadata
      handler has had a chance to take action as it unconditionally waits for
      MD_CHANGE_CLEAN to be cleared.
      
      [neilb@suse.de: return -EAGAIN, try GFP_NOIO]
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      b5470dc5
  8. 28 6月, 2008 9 次提交
    • D
      md: replace R5_WantPrexor with R5_WantDrain, add 'prexor' reconstruct_states · d8ee0728
      Dan Williams 提交于
      From: Dan Williams <dan.j.williams@intel.com>
      
      Currently ops_run_biodrain and other locations have extra logic to determine
      which blocks are processed in the prexor and non-prexor cases.  This can be
      eliminated if handle_write_operations5 flags the blocks to be processed in all
      cases via R5_Wantdrain.  The presence of the prexor operation is tracked in
      sh->reconstruct_state.
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      d8ee0728
    • D
      md: replace STRIPE_OP_{BIODRAIN,PREXOR,POSTXOR} with 'reconstruct_states' · 600aa109
      Dan Williams 提交于
      From: Dan Williams <dan.j.williams@intel.com>
      
      Track the state of reconstruct operations (recalculating the parity block
      usually due to incoming writes, or as part of array expansion)  Reduces the
      scope of the STRIPE_OP_{BIODRAIN,PREXOR,POSTXOR} flags to only tracking whether
      a reconstruct operation has been requested via the ops_request field of struct
      stripe_head_state.
      
      This is the final step in the removal of ops.{pending,ack,complete,count}, i.e.
      the STRIPE_OP_{BIODRAIN,PREXOR,POSTXOR} flags only request an operation and do
      not track the state of the operation.
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      600aa109
    • D
      md: replace STRIPE_OP_CHECK with 'check_states' · ecc65c9b
      Dan Williams 提交于
      From: Dan Williams <dan.j.williams@intel.com>
      
      The STRIPE_OP_* flags record the state of stripe operations which are
      performed outside the stripe lock.  Their use in indicating which
      operations need to be run is straightforward; however, interpolating what
      the next state of the stripe should be based on a given combination of
      these flags is not straightforward, and has led to bugs.  An easier to read
      implementation with minimal degrees of freedom is needed.
      
      Towards this goal, this patch introduces explicit states to replace what was
      previously interpolated from the STRIPE_OP_* flags.  For now this only converts
      the handle_parity_checks5 path, removing a user of the
      ops.{pending,ack,complete,count} fields of struct stripe_operations.
      
      This conversion also found a remaining issue with the current code.  There is
      a small window for a drive to fail between when we schedule a repair and when
      the parity calculation for that repair completes.  When this happens we will
      writeback to 'failed_num' when we really want to write back to 'pd_idx'.
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      ecc65c9b
    • D
      md: kill STRIPE_OP_IO flag · 2b7497f0
      Dan Williams 提交于
      From: Dan Williams <dan.j.williams@intel.com>
      
      The R5_Want{Read,Write} flags already gate i/o.  So, this flag is
      superfluous and we can unconditionally call ops_run_io().
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      2b7497f0
    • D
      md: kill STRIPE_OP_MOD_DMA in raid5 offload · b203886e
      Dan Williams 提交于
      From: Dan Williams <dan.j.williams@intel.com>
      
      This micro-optimization allowed the raid code to skip a re-read of the
      parity block after checking parity.  It took advantage of the fact that
      xor-offload-engines have their own internal result buffer and can check
      parity without writing to memory.  Remove it for the following reasons:
      
      1/ It is a layering violation for MD to need to manage the DMA and
         non-DMA paths within async_xor_zero_sum
      2/ Bad precedent to toggle the 'ops' flags outside the lock
      3/ Hard to realize a performance gain as reads will not need an updated
         parity block and writes will dirty it anyways.
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      b203886e
    • N
      Make sure all changes to md/dev-XX/state are notified · 52664732
      Neil Brown 提交于
      The important state change happens during an interrupt
      in md_error.  So just set a flag there and call sysfs_notify
      later in process context.
      Signed-off-by: NNeil Brown <neilb@suse.de>
      52664732
    • N
      Make sure all changes to md/sync_action are notified. · 72a23c21
      Neil Brown 提交于
      When the 'resync' thread starts or stops, when we explicitly
      set sync_action, or when we determine that there is definitely nothing
      to do, we notify sync_action.
      
      To stop "sync_action" from occasionally showing the wrong value,
      we introduce a new flags - MD_RECOVERY_RECOVER - to say that a
      recovery is probably needed or happening, and we make sure
      that we set MD_RECOVERY_RUNNING before clearing MD_RECOVERY_NEEDED.
      Signed-off-by: NNeil Brown <neilb@suse.de>
      72a23c21
    • N
      Allow setting start point for requested check/repair · 5e96ee65
      Neil Brown 提交于
      This makes it possible to just resync a small part of an array.
      e.g. if a drive reports that it has questionable sectors,
      a 'repair' of just the region covering those sectors will
      cause them to be read and, if there is an error, re-written
      with correct data.
      Signed-off-by: NNeil Brown <neilb@suse.de>
      5e96ee65
    • N
      Improve setting of "events_cleared" for write-intent bitmaps. · a0da84f3
      Neil Brown 提交于
      When an array is degraded, bits in the write-intent bitmap are not
      cleared, so that if the missing device is re-added, it can be synced
      by only updated those parts of the device that have changed since
      it was removed.
      
      The enable this a 'events_cleared' value is stored. It is the event
      counter for the array the last time that any bits were cleared.
      
      Sometimes - if a device disappears from an array while it is 'clean' -
      the events_cleared value gets updated incorrectly (there are subtle
      ordering issues between updateing events in the main metadata and the
      bitmap metadata) resulting in the missing device appearing to require
      a full resync when it is re-added.
      
      With this patch, we update events_cleared precisely when we are about
      to clear a bit in the bitmap.  We record events_cleared when we clear
      the bit internally, and copy that to the superblock which is written
      out before the bit on storage.  This makes it more "obviously correct".
      
      We also need to update events_cleared when the event_count is going
      backwards (as happens on a dirty->clean transition of a non-degraded
      array).
      
      Thanks to Mike Snitzer for identifying this problem and testing early
      "fixes".
      
      Cc:  "Mike Snitzer" <snitzer@gmail.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      a0da84f3
  9. 25 5月, 2008 4 次提交
    • N
      md: restart recovery cleanly after device failure. · dfc70645
      NeilBrown 提交于
      When we get any IO error during a recovery (rebuilding a spare), we abort
      the recovery and restart it.
      
      For RAID6 (and multi-drive RAID1) it may not be best to restart at the
      beginning: when multiple failures can be tolerated, the recovery may be
      able to continue and re-doing all that has already been done doesn't make
      sense.
      
      We already have the infrastructure to record where a recovery is up to
      and restart from there, but it is not being used properly.
      This is because:
        - We sometimes abort with MD_RECOVERY_ERR rather than just MD_RECOVERY_INTR,
          which causes the recovery not be be checkpointed.
        - We remove spares and then re-added them which loses important state
          information.
      
      The distinction between MD_RECOVERY_ERR and MD_RECOVERY_INTR really isn't
      needed.  If there is an error, the relevant drive will be marked as
      Faulty, and that is enough to ensure correct handling of the error.  So we
      first remove MD_RECOVERY_ERR, changing some of the uses of it to
      MD_RECOVERY_INTR.
      
      Then we cause the attempt to remove a non-faulty device from an array to
      fail (unless recovery is impossible as the array is too degraded).  Then
      when remove_and_add_spares attempts to remove the devices on which
      recovery can continue, it will fail, they will remain in place, and
      recovery will continue on them as desired.
      
      Issue:  If we are halfway through rebuilding a spare and another drive
      fails, and a new spare is immediately available,  do we want to:
       1/ complete the current rebuild, then go back and rebuild the new spare or
       2/ restart the rebuild from the start and rebuild both devices in
          parallel.
      
      Both options can be argued for.  The code currently takes option 2 as
        a/ this requires least code change
        b/ this results in a minimally-degraded array in minimal time.
      
      Cc: "Eivind Sarto" <ivan@kasenna.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      dfc70645
    • B
      md: allow parallel resync of md-devices. · 90b08710
      Bernd Schubert 提交于
      In some configurations, a raid6 resync can be limited by CPU speed
      (Calculating P and Q and moving data) rather than by device speed.  In
      these cases there is nothing to be gained byt serialising resync of arrays
      that share a device, and doing the resync in parallel can provide benefit.
       So add a sysfs tunable to flag an array as being allowed to resync in
      parallel with other arrays that use (a different part of) the same device.
      Signed-off-by: NBernd Schubert <bs@q-leap.de>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      90b08710
    • C
      md: kill file_path wrapper · 6bcfd601
      Christoph Hellwig 提交于
      Kill the trivial and rather pointless file_path wrapper around d_path.
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6bcfd601
    • A
      md: proper extern for mdp_major · 03de250a
      Adrian Bunk 提交于
      This patch adds a proper extern for mdp_major in include/linux/raid/md.h
      Signed-off-by: NAdrian Bunk <bunk@kernel.org>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      03de250a
  10. 30 4月, 2008 1 次提交
  11. 28 4月, 2008 1 次提交
    • D
      md: introduce get_priority_stripe() to improve raid456 write performance · 8b3e6cdc
      Dan Williams 提交于
      Improve write performance by preventing the delayed_list from dumping all its
      stripes onto the handle_list in one shot.  Delayed stripes are now further
      delayed by being held on the 'hold_list'.  The 'hold_list' is bypassed when:
      
        * a STRIPE_IO_STARTED stripe is found at the head of 'handle_list'
        * 'handle_list' is empty and i/o is being done to satisfy full stripe-width
          write requests
        * 'bypass_count' is less than 'bypass_threshold'.  By default the threshold
          is 1, i.e. every other stripe handled is a preread stripe provided the
          top two conditions are false.
      
      Benchmark data:
      System: 2x Xeon 5150, 4x SATA, mem=1GB
      Baseline: 2.6.24-rc7
      Configuration: mdadm --create /dev/md0 /dev/sd[b-e] -n 4 -l 5 --assume-clean
      Test1: dd if=/dev/zero of=/dev/md0 bs=1024k count=2048
        * patched:  +33% (stripe_cache_size = 256), +25% (stripe_cache_size = 512)
      
      Test2: tiobench --size 2048 --numruns 5 --block 4096 --block 131072 (XFS)
        * patched: +13%
        * patched + preread_bypass_threshold = 0: +37%
      
      Changes since v1:
      * reduce bypass_threshold from (chunk_size / sectors_per_chunk) to (1) and
        make it configurable.  This defaults to fairness and modest performance
        gains out of the box.
      Changes since v2:
      * [neilb@suse.de]: kill STRIPE_PRIO_HI and preread_needed as they are not
        necessary, the important change was clearing STRIPE_DELAYED in
        add_stripe_bio and this has been moved out to make_request for the hang
        fix.
      * [neilb@suse.de]: simplify get_priority_stripe
      * [dan.j.williams@intel.com]: reset the bypass_count when ->hold_list is
        sampled empty (+11%)
      * [dan.j.williams@intel.com]: decrement the bypass_count at the detection
        of stripes being naturally promoted off of hold_list +2%.  Note, resetting
        bypass_count instead of decrementing on these events yields +4% but that is
        probably too aggressive.
      Changes since v3:
      * cosmetic fixups
      Tested-by: NJames W. Laferriere <babydr@baby-dragons.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NNeil Brown <neilb@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8b3e6cdc
  12. 19 4月, 2008 1 次提交
  13. 05 3月, 2008 2 次提交
  14. 07 2月, 2008 3 次提交